Hi All,
Laurie Knight, Syd Curtis and Nicholas Talbot have made comment on the role
of the sexes in the antiphonal song (introductory whistle usually followed
by whipcrack and 2-3 note reply) of the Eastern Whipbird. Nicholas has
informed me that he sexed the bird as it gave the introductory whistle and
whipcrack (as Laurie suggested). The PhD student I was assisting was
actually studying the role of the antiphonal song in this species. I don't
think she ever observed a known female give the whipcrack (all birds were
colour-banded and sexed by measurements), i.e. only males were seen to give
this call (I make it clear here that you need to see the bird to be sure as
pairs can be very close to each other when giving antiphonal song and it
sounds like both whipcrack and reply come from the one bird, the timing can
be so precise - it is mind-boggling when you watch a pair and it sounds like
only one bird is making the noise!!! So it is easy for two birds to be
present but only one bird visible). I also don't think she observed males
giving the standard reply (i.e 'female' song).
However, having said this I scanned through HANZAB and reference is made to
apparent males being observed to give the reply and females being observed
to give the introductory note and whipcrack (in fact this bird was
apparently later shot and sexed as female - early days!), and the male to
give the complete antiphonal song alone. Obviously, I haven't read the
original sources and don't know how reliable these observations are (they
are generally old and one wonders how they sexed the birds while observing
them - except for the case where the bird was shot, but was it the bird that
called or just presumed to be?. In any case I make the point that it is
possible that the songs aren't 100% sex-specific, but are nearly so).
As Syd points out in duetting species it is not always the male that
initiates the duet. And Syd also rightly points out that often people tend
to assume it is the male, this occurred with the Western Bristlebird (and
some people continue to believe that the male initiates the duet) where it
isn't actually known which sex gives the first song, and I doubt that it is
even known for sure that the songs are sex-specific (as cited in HANZAB). I
observed a presumed pair of WBB's once and made audio recordings(although it
remains possible that a third or fourth bird was present- they are such
buggers to keep track of in dense heath!!!!) examining the recordings
spectrographically in conjunction with my notes on where the calls were
coming from suggested to me that the individual birds gave both the first
song (called 'A' song) and the reply song (called 'B'song), although never
both types of song within a singing bout, and that they have a repertoire of
types of these songs (i.e. different forms of 'A' song and 'B' song).
However, I am the first to admit this data is VERY VERY sketchy (the birds
were out of sight in the heath), but at least suggestive and a good basis
for further study.
Cheers, Dean
Oh Yes, and I apologise for another LONG email - I really should practice
being more succinct!. But I figure if people aren't interested they don't
have to read it!.
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